All grating sets for moire optical transducers have an inherent error in their line spacings. This error is periodic in nature and is due to the lack of precision of the line generating mechanism. Generally, there is very little that can be done to correct this type of inherent inaccuracy, but in the present situation something can be done. It has been discovered that optical functioning of the grating sets can be improved by choosing the correct parameters for the optical windows of the grating sets. This results in optimizing the grating sets such that the effects of the inherent error is kept to a minimum.